Processing tobacco



Sept. 11, 1962 H. B. PARMELE ETAL 3,053,259

PROCESSING TOBACCO Filed April 22, 1958 2 Sheets-Sheet 1 INVENTORSHARRIS B.PARMELE FRANK B.DOYLE 8s BY WILLIAM E.ROUTH Sept. 11, 1962 H.B. PARMELE ETAL 3,053,259

PROCESSING TOBACCO Filed April 22, 1958 2 Sheet 2 INVENTORS HARRIS a.PARMELE FRAN a. DOYLE a BY WILLI E. ROUTH Ir A 7'TOR/VEYS.

3,053,259 PROCESSING TOBAUCO Harris B. Parmele, Glen Ridge, N.J., FrankB. Doyle, Raymond, Ill., and William E. Routh, Greensboro, N.C.,assignors to P. Lorillard Company, New York, N.Y., a corporation of NewJersey Filed Apr. 22., 1958, Ser. No. 730,155 4 Claims. (Cl. 131140)This invention relates to processing tobacco and has particularreference to methods and apparatus for reclaiming fragmented tobacco ortobacco fines, converting the same into equivalent tobacco shreds andblending the same with cut tobacco for manufacture into cigarettes orother smoking tobacco products.

It is well known that a considerable percentage of fragmented leaftobacco or fines results from the normal processes of stemming, drying,casing, cutting and blending leaf tobacco to a form suitable for themanufacture of cigarettes and other tobacco products. These tobaccofines are high quality tobacco material and, if recoverable andconvertible without substantial change into usable form, would improvemany tobacco products as well as resulting in a considerable saving ofvaluable material which would otherwise be wasted or utilized ascomponents of agricultural fertilizers and pesticides.

Many proposals have been advanced for the reconstitution of tobacco invarious usable forms, but virtually all of them include a change in thecharacteristics of the tobacco, usually caused by the addition of asubstantial percentage of gum adhesives needed to bind the finelydividedtobacco particles in molded or sheet form in simulation of a strippedtobacco leaf for use as a cigar wrapper, for example, or cut intoribbons for blending with cigar or cigarette filler tobacco.

In accordance with the present invention, a process for reclaiming andconverting tobacco fragments or fines resulting as a by-product fromcigarette and cigar making processes substantially directly into tobaccoshreds suitable for blending with tobacco is provided, without thenecessity of first forming the reclaimed tobacco into sheets and thencutting or slicing the same into properlysized material for cigarettemanufacture and the like.

In a preferred process of the invention, the tobacco fragments or fineswhich are collected as a by-product of the cigarette and cigar makingprocesses are first screened to remove sand and other fine foreignparticles, the resulting cleaned tobacco fines are ground or otherwisecomminuted into particles of predetermined size, the ground material isagain screened to reject undersize particles and oversize particles arerecycled to the grinding stage. The ground tobacco of the proper size isthen impregnated with an aqueous solution humectant, sugar, and asuitable binder. The impregnation is conducted under such conditionsthat the solution is dispersed through the interior of the tobaccoparticles so that the impregnated material does not feel moist, cannotbe balled in the hand and resembles wood sawdust, although it maycontain as high as 40% water.

The granular tobacco mixture is fed to the valley between two contactingdriven rollers, one of which is smooth-surfaced and the other iscircumferentially slotted or grooved. The rollers are held in tangentialengagement with sufficient pressure so that the tobacco is confined toand compressed within the grooves or slots and is thus compacted intodiscrete strings or shreds having lengths not less than about one inchand up to six inches or longer. The shreds so formed are then dried toremove moisture down to about 20% and admixed with cut tobacco from thenatural stripped leaf in a proportion on the order of 1 to 20% by weightfor manufacture into cigarettes or other smoking tobacco products in theusual way.

It Wil lbe seen that the process and apparatus of this invention providean elficient and economical way of reclaiming high quality by-producttobacco fines and utilizing them to improve the finished smoking articlesuch as a cigarette.

A more complete understanding of the invention may be had by referenceto the accompanying drawings, in which FIGURE 1 is a flow diagramillustrating the tobacco reclaiming process and apparatus of thisinvention;

FIG. 2 is a plan view of the tobacco compacting and shred-formingmechanism of this invention;

FIG. 3 is an end elevation thereof as seen along the line 33 of FIG. 2;and

FIG. 4 is an enlarged fragmentary section through the grooved or slottedroller as seen along the line 44 of FIG. 3.

Referring to the flow diagram of FIG. 1, numeral 10 designates one ofthe boxes in which the tobacco fines such as dust, stems, conveyorsiftings and the like are collected as by-products from the cigar,cigarette and other tobacco product manufacturing processes. Beforebeing loaded into the boxes 10, the fines are passed over an mesh perinch screen to remove sand and other heavy fine foreign particles. Theboxes 10 are mounted on dollies or fitted with casters, wheels orrollers and conveyed to and emptied into a receiving hopper 11. Thesuction pipe 12 of a pneumatic conveyor 13 driven by a fan 14 carriesthe tobacco fines to one or more storage bins 15. Preferably, there area number of such bins 15, each receiving and storing a different type ofmaterial. Thus, one bin 15 may receive only by-product tobacco finesfrom a hopper 11 supplied by a box 10 from the stemmery, another bin 15may receive only shorts, another conveyor siftings, and so on.

The bottom of each bin 15 is provided with an individual rotarymotor-driven proportioning feeder 16, which deposits a predeterminedamount from each bin 15 on a belt-type conveyor 17. By preselecting thefeeders 16 and their rate of discharge, the proper blends of materialsfrom the several bins 15 may be provided.

The conveyor 17 discharges into a hopper 18 having a float switch 19which actuates a switch shutting off the driving motor 20 of theconveyor 17 when the hopper is filled and restarts the motor 20 when thelevel of the material in the hopper 13 drops below a predeterminedpoint. In a manner readily understood the float switch 19 may similarlycontrol the driving motor of any feeder 16 that is in operation at thetime the hopper 18 is filled or empty in order to preclude excessiveaccumulation of material on the conveyor 17 when it is stationary.

The hopper 18 is provided with a motor-driven proportioning feeder 21similar to feeders 16 for delivering the material to a belt flow-scale22. of known construction and adjusted to control the speed of feeder 21so that a predetermined weight of material per minute is fed byflow-scale 22 to the multi-stage motor-driven grinder 23'.

Grinder 23 may be a hammer mill, ball mill, or impact mill, and mixesand grinds the tobacco material to a size such that it passes through ascreen of 60 mesh per inch with about 80% smaller than mesh, so that theground material discharged from the mill 23 is finely-divided but notpowdered. This finely-divided material is drawn from the last stage ofthe mill or grinder 23 to storage bin 24 by the suction pipe 25 of apneumatic conveyor 26 driven by fan 27.

As it is required, the finely-divided tobacco material is fed toflow-scale belt 29 by a motor-driven proportioning feeder 28 similar tothe feeder and flow-scale combination 21, 22 previously described. Thismeasured material is fed by belt 29 to the hopper of motor-driven mixer30 where it is mixed with an aqueous solution or mixture of binder andhumectant supplied from tank 31 by pipe 32 at a predetermined ratecontrolled by valve 33.

Several forms of aqueous binder and humectant mix tures or solutions maybe provided in tank 31. For example, it may be a mixture of 85 parts ofsodium salt of carboxymethyl cellulose (CMC), 7.5 parts of the sodiumsalt of carboxymethyl-hydroxyethyl cellulose (CMHEC), 7.5 parts of guargum. The CMC, CMHEC and guar gum are added together in a dry form andmixed thoroughly in a twin-shell blender. The binder mixture is added tothe sugar-humectant solution which has been heated to 85 C. Thesugar-humectant solution consists of 6.45 parts of Nulomoline (invertedsugar solution), 3.85 parts of glycerine, 0.65 parts of propyleneglycol, 0.01 part of methyl-p-hydroxybenzoate (MPHB), and 89.04 parts ofwater. Six pounds of dry binder are added to 154.0 pounds ofsugar-humectant solution. This binder-sugar-humectant solution has aviscosity of about 36,000 centipoises at 69 C.

Another suitable aqueous binder and humectant solution comprises 50parts of corn starch and parts of the above sugar-humectant solutionmixed with 200 parts of water. The resulting binder-sugar-humectantsolution has a viscosity of about 36,000 centipoises at 69 C.

About 160 pounds of either binder-sugar-humectant solution from tank 31are fed to mixer 30 together with 190 pounds of the powdered tobaccomaterial and 10 pounds of cellulose fibers, which are added toflow-scale 29 with the tobacco from feeder 28. The cellulose fibers maybe alpha-cellulose flock, shredded cigarette papers, or othersubstantially ash-free natural or synthetic fibers which are odorlessand nontoxic when burned.

The resulting mixture consists of tobacco particles surface-coated withthe binder-sugar-humectant solution but not materially impregnatedtherewith. Thus, the tobacco material is damp with the solution but itis not wet or doughy, but is more dry than wet so as to be readilyfluent or flowable. This mixture is discharged from mixer 30 throughpipe 34 leading to dispersing machine 35, which contains a motor-drivenbeater-screw or propeller 36, and may be a pressure muller, vacuumimpregnator, pug mill, extrusion apparatus, or a high speed centrifugalmixer, examples of which are marketed under the trade names Votator,Entoleter, etc. The machine 35 accordingly impregnates or introduces thesurface-carried binder-sugar-humectant solution into the interior of thetobacco particles which initially had a moisture content of about 8 toabout In some instances the dispensing machine 35 will make premixing inmixer 30 unnecessary.

The resulting tobacco material discharged by machine 35 to suction pipe37 is a homogeneous flowable mixture of solid tobacco andbinder-sugar-humectant solution containing about 30 to about 40% water,but it does not feel moist to the touch, cannot be balled in the handand somewhat resembles slightly damp wood sawdust.

The suction pipe 37' of the pneumatic conveyor 38 driven by fan 39conducts the dispersed fluent tobacco material to a storage bin 40 fromwhich it is metered by motor-driven proportionary feeder 41, similar tofeeder 16, to the suction pipe 42 of a pneumatic conveyor system drivenby fan 43 for supplying storage containers 44. Storage containers 44 areshown schematically in FIG. 1 as comprising a series of closed chambers45, nine being shown, but there may be more or less depending uponrequirements. Each chamber 45 is normally closed by a valve 46 and isfilled with the fluent material from storage bin 40.

When one of the valves 46 is opened, and with valve 47 in eduction pipe48 closed, the contents of the chamber 45 corresponding to the openedvalve 46 are discharged into storage bin 50 through pipe 51. Similarly,other chambers 45 may be evacuated to bin 50 by opening thecorresponding discharge valve 46. This may be done manually, butpreferably it is done automatically by means of a float switch 52 in bin50 and responding to drop in the level of material in bin 50 to open avalve 46 electrically and reclose it when the level in bin 50 rises to apredetermined height. The valves 46 may be connected in parallel withfloat switch 52 so as to operate individually as required or a separatebin 50 and float switch 52 for each storage chamber 45 may be provided,depending upon the volume of stored material to be handled.

When all valves 46 are closed and the corresponding chambers 45 filled,valve 47 is opened automatically and the dispersed material from storagebin 40 is returned thereto via pipes 42 and 48. When the pressure at thefeeder 41 exceeds atmospheric, weighted valve 53, normally closingdischarge pipe 54 from fan 43, opens and vents excess air and anyentrained material to the dust house, not shown, and to which theexhaust of fans 14, 27 and 39 also are connected.

A regulated flow of the impregnated tobacco material is supplied fromstorage bin or bins 50 by a motor-driven proportionary feeder 55,similar to 16, to a belt type flow-scale 56, similar to flow-scale 22,and whose flow rate is so adjusted to hopper 57 that the valley betweenrollers 58 and 59 is maintained level filled.

Referring now to FIGS. 2, 3 and 4, showing the rollers 58 and 59 inenlarged scale with their accompanying mechanism, it will be seen thatroller 58 is journalled in fixed bearings 60 mounted on a suitable baseplate casting 61 and that roller 59 is journalled in arms 62 pivoted at63 on base casting 61. Pivoted arms 62 and consequently roller 59 areurged toward roller 58 by strong coiled tension springs 64 so thatroller 59 engages roller 58 with considerable pressure for a purpose tobe described. Alternative pressure means, such as hydraulic cylinder andpiston combinations or compression springs and the like may be employedto urge rollers 58 and 59 together instead of the tension springs 64.

As is shown particularly in FIG. 2, roller 58 is grooved or slottedcircumferentially and preferably is of larger diameter than roller 59,which is smooth surfaced. The surfaces of rollers 58 and 59 preferablyare made of surface-hardened steel and are accurately machined so thatthe ridges, ribs or lands 65 that are formed between the circumferentialslots or grooves 66 engage the smooth surface of smaller roller 59 atthe line of tangential contact between them so as to confine the tobaccomaterial fed between the rollers from hopper 57 to the grooves or slots66 without permitting any of it to enter between the lands 65 and thecontacting surface of smooth roller 59. This confining and limitingaction is not only provided by the sharply-defined lands 65 but also bythe considerable pressure with which the rollers 58 and 59 are forcedtogether by the springs 64, with the result that the tobacco material islaterally or transversely compacted in the slots or grooves 66 asdistinguished from the axial or longitudinal compaction effected by anextrusion process. The tobacco material is accordingly formed with theaid of the sugar-binding-humectant content thereof, into elongatedstrings or shreds 67 which are sufliciently strong to be self-sustainingto a substantial degree, such that they break off into lengths not lessthan about one inch and up to about six inches or longer as they fall bygravity from between the rollers 58, 59, as is shown in FIG. 3.

The cross-sectional dimension or diameter of the shreds 67 is largelydetermined by the use to which they are to be put. If they are to beblended with cut tobacco for cigarette manufacture, they are ofsubstantially corresponding dimensions. Thus, it has been found that anaxial width of about .033 inch and a radial depth of about .006 to .020inch is satisfactory depending on the end use. A generally rectangularcross-section for the groove or slot 66 has been found to besatisfactory, although for uses such as for smoking tobacco or cigarfiller blending, larger dimensions and a different shape of slot orgroove cross-section, such as V-shaped or semicircular, for example, maybe required.

The width of the ribs, ridges or lands 65 should be as narrow aspossible for optimum output of the machine, but because of theconsiderable pressure with which the rollers 58 and 59 are heldtogether, they must be sufficiently wide to preclude grooving the smoothroller 59 and strong to withstand being distorted. Thus, a land width ofabout .017 inch has been found to be a satisfactory minimum dimensionfor manufacture of cigarette blending shreds, although that dimensionmay be increased as desired and where lower pressures are used, may bedecreased slightly. With these dimensions, the proper pressure should besuch that the rollers cut thin paper, e.g., cigarette paper, to shreds.

As shown in FIGS. 2 and 3, the grooved roller 58 is fitted with a spurgear 68 driven by spur gear 69 from a suitable source of power like anelectric motor, not shown. Smooth roller 59 is not driven except byfriction from grooved roller 58, so that both rollers 58 and 59 rotateat the same peripheral speed, without erosive slippage between them.

The shreds 67 are stripped from the slots or grooves 66 by the springfingers of a comb-shaped stripper 70, the tips of these fingersprojecting into the slots or grooves in the manner shown in FIG. 3. Thestripper 70 is mounted on base plate 61 and the pressure of its fingerson the bottoms of the corresponding slots or grooves 66 may be adjustedby screw 71. A spring scraper 72 mounted on base plate 61 engages thesurface of smooth roller 59 to clean off any surplus material which mayhave adhered thereto. This surplus material may be discharged to areceptacle, not shown, for return to storage bin 24, for example.

The formed shreds 67 of reclaimed tobacco fines are deposited by theforming rollers 58, 59 on a conveyor belt 73 preferably made ofstainless steel, and driven at the same surface speed as the rollers 58,59 by suitable means, not shown. The shreds are passed by belt 73through a drying chamber 74 where it is heated from below by suitableheating means, such as gas burners, and from above by radiant heaters orcombinations thereof. In the drying chamber 74, the shreds are dried toabout 20% moisture content.

The shreds are discharged by belt 73 to the chute 75 of a vibrating orshaking type separator 76 where any agglomerated or Siamese shreds areremoved and returned by pneumatic conveyor system 77, 78, 79 to theinput pipe 34 of the dispersion machine for reprocessing. Those shredswhich are not oversize are passed by screen 76 to vibrating screen 80which passes the fines to suction pipe 81 for return to raw materialstorage bin 24.

The proper sized shreds 67 of tobacco fines reclaimed according to thisinvention are discharged from separator screen 80 to chute 82 whichdeposits them on driven conveyor 83 for blending with cut leaf tobaccoon conveyor 84 receiving the same from rotary kiln drier 85. Theproportion of reclaimed shreds from belt 83 is 2 to by weight, 98 to 90%by weight, of cut tobacco on belt 84 which accordingly deposits the samein this proportion into a rotary kiln type of cooler 86- which cools andblends the reclaimed tobacco shreds and cut tobacco leaf for use inmanufacture of cigarettes or other tobacco products in cigarette machine88 to which it is carried from cooler 86 by conveyor 87, which may,instead, carry the blend to storage for use when required.

The process and apparatus of this invention will be readily understoodfrom the foregoing description of the schematic flow diagram of FIG. 1and the shred making machine illustrated by FIGS. 2, 3 and 4, and theprocess may be further exemplified by the following tabulation ofingredients and proportions of a typical composition of the reclaimedtobacco material supplied to the shredforming rolls 58 and 59:

Tobacco Powder and Cellulose Fibers Percent Lbs.

Cigarette Dust 50 0 100 Slivers 38.0 76 #8 Bright (Particles passing aNo. 8 screen 5.0 10 #8 Burley (Particles iassing a No. 8 screen) 2.0 4Cellulose Fibers (S01 a-Floc BW40) 5.0 10

Binder Percent Percent Material Lbs. Total Added to Binder TobaccoSugar-Humectant Solution Percent Percent Material Lbs. Total Added toLiquid Tobacco Nulomoline 9. 93 6. 45 4. 97 Glycerine 5. 93 3. 2. 97Propylene Glycol 1.00 0.65 0.50 Methyl p-hydroxybenzoate 0.02 0.01 0.01Water 137. 12 89. 04 68. 56

Total 154.00 100.00 77. 01

It will be understood that the formulations, methods and apparatusherein described are illustrative of the invention, which is not to belimited thereby, except within the scope of the appended claims.

We claim:

1. A method of reclaiming tobacco resulting as. a waste byproduct of themanufacture of smoking tobacco products, which comprises grinding thetobacco to about 60 to 100 mesh particle ize, separating therefrom anytobacco powder formed by grinding said tobacco, mixing the groundtobacco with a binder in an amount sufficient to moisten said tobaccobut insufiicient to render said tobacco wet and capable of being balledby hand, and passing the resulting mixture between a smooth surfaceroller and a grooved roller in rolling contact to compress the resultingmixture into filamentary shreds having the approximate dimensions of cutleaf tobacco for admixture with cut natural leaf tobacco.

2. A method of reclaiming tobacco resulting as a waste by-product of themanufacture of smoking tobacco products, which comprises grinding thetobacco to about 60 to 100 mesh particle size, separating therefrom anyto bacco powder formed by grinding said tobacco, increasing the naturalmoisture content of the tobacco to between about 30 and about 40 percentby weight, and passing the moistened ground tobacco between a smoothsurface roller and a grooved roller in rolling contact to compress themoistened ground tobacco into filamentary shreds having approximatelythe dimensions of cut leaf tobacco for admixture with cut natural leaftobacco.

3. A method of reclaiming tobacco resulting as a waste by-product of themanufacture of smoking tobacco products, which comprises grinding thetobacco to about 60 to 100 mesh particle size, separating therefrom anytobacco powder formed by grinding said tobacco, impregnating the groundtobacco with an aqueous binder solution in an amount sufficient tomoisten the tobacco but insuflicient to render said tobacco wet andcapable of being balled in the hand, and passing the impregnated tobaccobetween a smooth surface roller and a grooved roller in rolling contactto compress the impregnated tobacco into filamentary shreds foradmixture with cut natural leaf tobacco.

4. A method of reclaiming tobacco resulting as a waste by-product of themanufacture of smoking tobacco products, which comprises grinding thetobacco to about 60 to 100 mesh particle size, separating therefrom anytobacco powder formed by grinding said tobacco, impregnating the groundtobacco with an aqueou humectant solution in an amount sufficient tomoisten the tobacco but insufficient to render said tobacco Wet andcapable of being balled in the hand, and passing the impregnated tobaccobetween a smooth surface roller and a grooved roller in rolling contactto compress the impregnated tobacco into filamentary shreds foradmixture with cut natural leaf tobacco.

References Cited in the file of this patent UNITED STATES PATENTSStayman Jan. 15, 1867 Kimball June 30, 1874 Kimball Apr. 5, 1881 EversOct. 25, 1910 Olson Dec. 9, 1924 Grunauer Feb. 16, 1932 Dahlstrom et alMar. 14, 1939 Deich May 16, 1939 Wells et al. Jan. 6, 1948 Jurgensen etal. May 3, 1955 Bandel Nov. 6, 1956 Frankenburg et al Apr. 15, 1958Samfield et a1. Aug. 5, 1958 FOREIGN PATENTS Germany Sept. 18, 1925

